Going to another cafe to buy your coffee doesn't include a door charge of €300 just so you can start getting your coffee there. Sure you can get it from those other devices but there's a large cost up front to switching device.

I originally started on Android and moved to iOS to check the other side. I find it annoying that I can't really use Kindle like I could before.. Or tell Siri to play something from Spotify. I'm forced to use Apple alternatives and it's the reason I'm moving back to Android when my phone dies.

True, the analogy is probably broken.

You certainly can ask Siri to play music from Spotify, I don't know who said you can't. That was added last October with iOS 13. I have no idea what's happened with Kindle, but I use Google Play and Kobo books as well as Apple's Books, and everything works fine for reading. If not being able to purchase books on the device bothers you so much, fair enough, it's your choice, but nothing much has stopped me from finding the cheapest source of an ebook in epub format and reading it.